Re: [Geographiclib-users] defining a projection (modified)

[Charles K. <cha...@sr...>]

Hugh,

You can perform this projection (but without the false easting and false
northing offsets) with

   TransverseMercatorProj -l 145 -e 6378160 1/298.25 -k 1

E.g.,

echo -37 145.5 | TransverseMercatorProj -l 145 -e 6378160 1/298.25 -k 1
->
44506.1549112743 -4096642.0780917532 -0.3009124466146239 1.0000243910016182

echo 44506.1549112743 -4096642.0780917532 |
TransverseMercatorProj -l 145 -e 6378160 1/298.25 -k 1 -r
->
-37.000000000000007 145.500000000000000 -0.3009124466146240 
1.0000243910016182

The 3rd and 4th numbers in the output are the meridian convergence and
scale.  Applying the false easting and false northing offsets is
straightforward.  Use "TransverseMercatorProj --help" for full
documentation on this utility.

You can also carry out the projection in C++ code using the
TransverseMercator class.

   --Charles

On Mon, Dec 10, 2012 at 4:19 AM, hugh <hdixon@...> wrote:
 > Hi,
 > I am wanting to convert eastings and northings into lats and longs.  I
 > am a civil engineer, not a surveyor, but have dabbled with projections
 > in the past so know a little.
 >
 > I have been told my E / N are in a pseudo AMG (UTM) projection.  I
 > have been given the following parameters:
 >
 > PSEUDO AMG 1966
 >
 > Projection: Transverse_Mercator
 > False_Easting: 500000.000000
 > False_Northing: 10000000.000000
 > Central_Meridian: 145.000000
 > Scale_Factor: 1.000000
 > Latitude_Of_Origin: 0.000000
 > Linear Unit: Meter (1.000000)
 >
 > Geographic Coordinate System: GCS_Australian_1966
 > Angular Unit: Degree (0.017453292519943299)
 > Prime Meridian: Greenwich (0.000000000000000000)
 > Datum: D_Australian_1966
 >   Spheroid: Australian
 >     Semimajor Axis: 6378160.000000000000000000
 >     Semiminor Axis: 6356774.719195305400000000
 >     Inverse Flattening: 298.250000000000000000
 >
 >
 > To me this looks like the standard UTM, except for the scale factor.
 > Is this correct?
 >
 > Any someone suggest an open source library I can use to convert these
 > co ordinates into lats and longs.
 >
 > Thanks
 > Hugh